Till now conical refractory purge plugs (purge sleeves), by means of which gas is introduced into the molten metal, or conical refractory sleeves, which respectively form an outlet opening, are generally inserted into correspondingly formed nozzle brick openings. They are separated from the latter by narrow mortar joints (approximately 1 to 3 mm wide). When the worn purge plugs or sleeves break loose, which happens due to pulling, chiselling out using pneumatic hammers, burning out, squeezing out etc., these parts are time and again destroyed, the remains being left hanging in the respective nozzle brick opening. These remains, as well as mortar remains and any steel tongues, must be removed, which is very labour-intensive. When they break loose, and during the cleaning steps, damage to or destruction of the nozzle brick can occur.
Generally time-consuming nozzle brick repairs are necessary after every purge plug or sleeve change. The cleaning steps on the hot, refractory parts are dangerous and constitute heavy labour. When applying the mortar to the purge plug or to the sleeve an uneven mortar thickness can occur, or during the manually implemented mounting of the purge plug or the sleeve the mortar can become uneven in some places or even be totally stripped off locally. This leads to known problems such as premature wear in the region of the joints, the penetration of steel into the joint and even the risk of breaking through.